Depopulation affects service and infrastructure provision, quality of life, and the long-term social, demographic, and economic viability of communities and regions. It is also likely to disproportionately affect some groups more than others. The main objective of this project is to remedy our lack of knowledge about the geography and pervasiveness of population decline in United States, the characteristics of those living in depopulating areas, and the demographic change occurring in locations losing population. Population change data are integrated with information regarding the demographic sources of population loss (i.e. migration versus natural decline), characteristics of inhabitants (age structure, racial/ethnic composition, and poverty levels), and measures of change in these variables for U.S. counties and, where appropriate, census tracts. The investigation will show how declining areas differ from growing areas in terms of demographic characteristics as well as recent change in those characteristics. Furthermore, this research will generate new information about the characteristics of those exposed to population decline at multiple spatial scales, which will provide a more nuanced identification of those vulnerable to the impacts of population decline. To achieve its objectives, the project will use geographical information systems (GIS), descriptive analysis, and spatial regression models and exploratory spatial statistics. Datasets will be created that integrate county and census tract data for 2000-2010 as well as county-level historical population data, estimates of the components of demographic change for 2000-2010, and county-to-county migration flow data for the same period. These data will be used to develop a typology of population change across U.S. counties based on population change for the area, its historical change, and the change experienced by surrounding areas. Data are tabulated across types of areas in order to measure the demographic characteristics of those exposed to each category of population change and to assess community- and region-level demographic changes occurring in both depopulating and growing places. Explanatory regression models are constructed that estimate the impact of location in a particular type of changing area on demographic outcomes. Spillover effects across neighboring areas are estimated with spatial regression models.